It is well known in the art that down or down compositions provide excellent thermal insulating value for the reason that the down is very fluffy and traps air which provides excellent insulation. However, because down or compositions thereof is very fluffy, when used as an inner lining for articles of clothing it provides a very puffy appearance. The thicker the fluff in the inner lining, the more insulating value is achieved and the article of clothing is puffier. This has a disadvantage in that the article of clothing becomes very large and disproportionate to the person wearing the article of clothing. For this reason down is utilized in only certain articles of apparel and not others where its insulating value may be desirable.
Because of the above existing problems, other insulating materials are used as inner linings, such as synthetic fibers. However, synthetic fibers cannot replace the excellent thermal insulation properties of down which is a natural product. Also, down is not a polluting agent when released in the environment as are resinous fiber materials.
Another problem with down-fill lining is that the down can be displaced within the lining and congregate in certain portions thereof where it then provides increased insulation while in other portions of the lining the insulating value is reduced. A still further disadvantage of using down-fill interlining, wherein the interlining has a body covering portion as well as arm portions secured thereto, is that the padding or insulation in the armpit region of the inner lining doubles in thickness due to the fact that when the article of clothing is worn the arm extends against the body, thus providing double thickness insulation under the armpit. This makes it very uncomfortable to the wearer and restricts arm movement to some degree.